Analytical procedures for cyclic nucleotides and their associated enzymes in plant tissues

Abstract

A substantial body of published information has accrued indicating the presence in higher plants of all the components needed for functional cyclic nucleotide-regulated control systems. In order to consolidate this and to stimulate further research, the methodology currently available for the analysis of cyclic nucleotides in plants and for assaying their associated enzymes is critically reviewed. The extraction of cyclic nucleotides, their separation by high performance liquid chromatography and identification using the latest techniques in mass spectrometry is described, and the determination of these compounds by radioimmunoassay and by saturation binding assay is examined. Assays for the cyclase, cyclic nucleotide phosphodiesterases and protein kinases are critically appraised. Other cyclic nucleotide-binding proteins are considered. The validity and accuracy of the various methods in connection with plant analysis are evaluated.

Nitric oxide regulates K + and Cl - channels in guard cells through a subset of abscisic acid-evoked signaling pathways

“…Plant guanylate cyclases are structurally different from the animal enzymes, and an NO sensitivity has yet to be identified (38). Nonetheless, cGMP has been unambiguously demonstrated in plants by mass spectrometry (39), and an NO-sensitive guanylate cyclase is implicated in several plant tissues including Arabidopsis and Vicia guard cells, for which the physiological effects of NO are suppressed by ODQ, an inhibitor of mammalian NO-sensitive guanylate cyclase (15,26). Thus it seems that all the major elements of an NO-driven and Ca 2ϩ -coupled signal cascade occur and function in Vicia guard cells.…”

Defense gene induction in tobacco by nitric oxide, cyclic GMP, and cyclic ADP-ribose

“…Samples were treated and prepared as described by Brown and Newton (16). cGMP was estimated by using a 125 I-based radioimmunoassay and a commercially available kit from Amersham.…”

“…cGMP was estimated by using a 125 I-based radioimmunoassay and a commercially available kit from Amersham. To increase the sensitivity, the samples were acetylated (16). cGMP was quantified by comparison to pure cGMP standards.…”

“…However, two important downstream components of NO signaling in mammals, cGMP and cyclic ADP-ribose (cADPR), are functional in plants. cGMP appears to be important in light-mediated signal transduction and ion channel regulation (16)(17)(18). In addition, cGMP can stimulate the induction of genes encoding chalcone synthase (CHS) and ferredoxin NADP ϩ oxidoreductase and can initiate anthocyanin biosynthesis in soybean (17).…”

Analytical techniques for trace organic compounds - VI. Application of liquid chromatography-mass spectrometry (Technical Report)

“…Modified nucleobases ( 126) and analogs were determined ( 127,128), and with continuous flow FAB nucleotides and their metal complexes were studied ( 129). cyclic nucleotides from plant tissues were studied ( 130).…”